Treatment of hydrocarbons



Patented Sept. 15,1942? TREATMENT or nYDRoCARBoNs Raymond E. Schaacl,Chicago, Ill., assignor to Universal Oil Products Company, Chicago,Ill., a corporation of Delaware Application September 13, 1940, SerialNo. 356,594

'l'his invention relates to the treatment of hydrocarbon fractions oflow antiknock value such as straight-run gasolines. and naphthasproduced from parainic and naphthenic crudes or from any other sourcefor the purpose of producing therefrom substantially saturated motorfuel of relatively high antiknock value.

In a more specic sense the invention 1s concerned with a process` forconverting essentially parailinic and naphthenic hydrocarbons into agaseous product rich in isobutane, an intermediate product containingbranched chain pentanes and hexanes, and a higher boiling liquid productwhich may be dehydrogenated to normally liquod olefinic hydrocarbonsutilizable for alkylating said gaseous product rich in lsobutane to forma substantially saturated alkylate of improved antiknock value. Saidsubstantially saturated alkylate maybe increased further in antiknockvalue by a moderate addition of lead tetraethyl.

The formation of isobutane and of other isoparaiiins or more highlybranched chain paraln hydrocarbons from less branched chain liquidparains and from naphthenic` hydrocarbons is desirable because of thegenerally higher antiknock value of the isomeric parailn hydrocarbons soformed. Furthermore, the branched chain paraftlns, both gaseous andliquid, are generally more reactive than the corresponding normalhydrocarbons and consequently these may be utilized in the production ofother branched chain parailins by so-called alkylation reactions in thepresence of suitable catalysts.

In one specic embodiment the present invention comprises a process forconverting a substantially saturated liquid hydrocarbon fraction ofrelatively low antiknock value into a substantially saturated motorfuelof improved antiknock' valueA which comprises treating said hydrocarbonfraction with aluminum chloride, hydrogen, and hydrogen chloride toproduce substantial yields of isobutane, a fraction containing branchedchain pentanes and hexanes, and a higher boiling hydrocarbon fraction;catalytically dehydrogenating said higher boiling hydrocarbon fractionto form a substantial yield of normally liquid olelins; and subjectingsaid isobutane and said normally liquid oleflns to catalytic alkylationto form a substantially saturated alkylate comprising essentiallyhydrocarbons of motor fuel boiling range and high antiknock value.

'I'he substantially saturated hydrocarbons preferred as charging stockfor the process of this invention and comprising essentially parailinsand naphthenes are normally liquids with relatively low antiknockvalues. Such substantially saturated hydrocarbons are recovered inconsiderable quantities in the oil refining industry by distillation ofparafilnic, naphthenic, and mixed base crudes. Further, paraflins occurin substantial amountsin other gasolines and in the higher' boilingconstituents of natural gas commonly v known as casing head gasoline, incertain hydrocarbon materials produced synthetically, and ingasolinesproduced in relatively high yields by the cracking ofrelatively heavy petroleum fractions. In the case of cracked gasolinesproduced from paraflinic and naphthenic oils, the

relative proportions of isoparailins, normal part mate limits of and 500F. In'the absence of an added hydrogen-containing ga`s, isomerizationand destructive hydrogenation vreactions are accompanied by theformation of undesirable products, rapid sludge formationon the aluminumchloride catalyst, and an early decrease in catalytic activity. y

It appears that anhydrous aluminum chloride as generally obtainablecontains Ma small but necessary percentage of hydrogenchloride and/ orof oxygen compounds, such as hydroxy-aluminum dichloride, or otheroxygen derivatives formed by the reaction of pure aluminum chloride withrelatively minor proportions of water or of other oxygen compounds.Further, it has been found advisable to add small but denite quantitieso! hydrogen chloride to the hydrocarbon fraction being contacted withthe aluminum chloride-con- .taining catalyst in order to prevent foulingof the catalyst and a consequent diminution in its hydrocarbonconverting activity.

According to the process of the present invention, it has been foundthat substantially anhydrous aluminum chloride may be subjected to Icontact with a hydrocarbon fraction comprising essentially paramns andnaphthenes at an ele-` vated temperature and under a hydrogen pressureinthe presence of hydrogen chloride to convertinto isoparaflins asubstantial proportion of the fraction charged and to producesimultaneously a substantial yield of isobutane. The use ofsuperatmospheric hydrogen pressure is of con- 'siderable importance ineiecting hydrocarbon i desiredI products, but also results in asubstantial conversion of the catalyst into a sludge-like material withrelatively low catalytic activity.

Continuous destructive hydrogenation of naphtha may be eiected bypassing the naphtha through a reactor'where it may be subjected tocontact with hydrogen, hydrogen chloride, and aluminumv chloride or a`mixture of aluminum chloride with a member selected from the group ofso-called Friedel-Craftsv catalysts consisting of `ferric chloride, zincchloride, zirconium chloride,7 and boron uoride. Or, the destructivehydrogenating catalyst may consist of a so-called Friedel-Craftscatalyst selected fromthe group consisting of ferric chloride, Yzincchloride, zirconium chloride, and boron fluoride.

To the hydrocarbon fraction being treated it is preferable to add anamount of hydrogen chloride usually Within the llimits of O.5-10% byweight of said hydrocarbon fraction,`since continuous operation mayotherwise remove small but desirable amounts of hydrogenchloride oftenpresent as impurity in substantially anhydrous aluminumchlorideavailable commercially. Because ofthe shorter time of contact of thehydrocarbon fraction with the catalyst in such continuous conversions,the operating temperature y used isy generally higher than that requiredto effect a similar change in batch operations. After lsuch treatmentwhich may be. in liquid, vapor, or mixedphase, depending upon thehydrocarbon treated and the'temperatureand pres- A sure conditionsvemployed,` the hydrocarbon material may be removed from the catalyst andVfractionally distilled to separate selected fractions of conversionproducts while unconverted or incompletely converted fractionscomprising essentially `those boiling abovehexane may be subjected to`dehydrogenation to form olenic hydrocarbons utilizable in alkylatingvisobutane formed in the destructive hydrogenation step of :fthe processas hereinabove set forth.

l Destructive hydrogenation products boiling above butanes may `hexanemixture and-a higher'boiling'substantially saturated fraction containingheptanes and higher l boiling lparaiiins. heptanes and higher subjectedto contact with a dehydrogenating cat- Lalyst preferably inthefpresencae-o'i` from about per centof water vapor at be separatedinto a pentane- Said fraction containing boiling parafns may be 0.1 `toabout 10 mole a temperature between about `800 and l200 F. 'under a.pressure-'of present Yin the fraction'Y so" aromatic hydrocarbons. It ahydrogen-containing gas from ,substantially atmospheric to approximately:150,.poundsl per square :inch to vform a product containing asubstantial .proportion of normally liquid olens.

- thenic hydrocarbons ,subjected to dehydrogenation may be 'convertedsimultaneously into iis preferable to have -piesent inthe mixture -beingcontacted with the .dehydrogenating catalyst whichfrnay comprise acomposite of a substantially inert carrier selected from the groupconsisting of alumina, magnesia, silica, thoria, titania, zirconia, andzinc oxide, and a relatively smaller proportion of an oxide of anelement selected from the members of the left-hand columns of groups Vand VI of the periodic table consisting of vanadium, columbium,tantalum, chromium, molybdenum, tungsten, and uranium.

The carriers or supports above referred to have relatively low catalyticactivity while the oxides of the elements mentioned, which may be usedsingly or as mixtures, are of relatively high catalytic activity andfurnish by far the greater proportion of observed catalytic effects. Theoxides cf these several elements vary in any given reactioncomprisedwithin the scope of the invention, this variation may be greater in thecase of different types of dehydrogenation reactions.

The isobutane obtained by destructive hydrogenation of the naphtha orother hydrocarbon I fraction charged may be alkylated by the normally.liquid olefins formed in the dehydrogenating stage of the process. Thisalkylation may be carried out in the presence of a suitable catalystsuch as sulfuric acid, hydrogen fluoride, aluminum chloride withhydrogen chloride, and boron fluoride with hydrogen uoride at sometemperature between about *-15 and 210 F. under suicient pressure tomaintain in liquid phase a substantial proportion of the isobutanepresent. In general from approximately 4 to about 20 molecularproportions of isobutane or other isoparaim should be present in thereaction zone for each molecular proportion of olen introduced theretotol avoid polymerization reactions.

Alkylation of isobutane-by a normally liquid c-len formed` ashereinabove set forth may be carried out also in the presence of aphosphoric acid-containing catalyst conveniently employed in the form ofa solid mixture or granular precalcined composite with a generallysiliceous adsorbent such as diatomaceous earth. Such a preferredcomposite alkylating catalyst is the socalled solid phosphoric acidcatalyst found useful also in polymerization reactions and described inU. S. Patent No. 1,993,513 and others. In the presence of thisphosphoric acid-containing material, isobutane and otherisoparains maybe alkylated vby oleiins at a temperature within the approximate limitsof 600 and 900 F.

under a pressure between about 1000 and about 3000 pounds per squareinch to form a product containingxa substantially saturated alkylate ofrelatively high antiknock value.

These diierent alkylating catalysts, which may be usedalternatively, arenot necessarily equivalent in their, action, and the conditions oftemperature,vpressure, and time employed for any -given alkylation aredetermined byrthe catalyst,

thecompositionof the reaction mixture, and by other factors. l

For the purpose of illustrating the combination of `steps characteristicof the presentk invention, the attached drawing shows diagrammatically atypical processiiow for treating paraflnic and/or `naphthenichydrocarbon fractions to produce Vsubstantial yields of isobutane, amixture'ofl branched chain pentanes and hexanes,l and a higher boilingfraction which may -be catalytically dehydrogenated to oleflnsutilizable in alkylating' said isobutane to form 'a substantia lysaturated alkylate of high antiknock value.'I

Referring to the drawing, a naplitha fraction 'of relatively lowantiknck value A:comprising essentially paraillns and naphthenessubstantially free from olefins and/or aromatics may be introlimits of300 `and 2500 pounds per square inch. Destructive hydrogenation zone zmaycontain mixing devices of suitable design for effecting con- 100 and500 F. and preferably under a superatmospheric pressure within the.approximate tact between the hydrocarbons and the aluminum'Ichloride-containing catalyst consisting of aluminum, chloride sludgeformed in the process recycled through lines I and 8 and fresh aluminumchloride introduced through line 3 to destructive hydrogenation 4zone 2or alternatively through line 4 to line I, already mentioned.

The products of destructive hydrogenation may be Withdrawn from zone 2through line 5 to separation zone 6 which may comprise settling,stripping, and fractional distlling equipment of adequate design forseparating a used aluminum chloride-containing sludge, a gas containinghydrogen and hydrogen chloride, an isobutane fraction, a mixturecomprising essentially'branched 1 chain pentanes and hexanes, and ahigher boiling `fraction of relatively low yantilmock value. Fromlseparation zone 6 the used catalyst sludge may be directed through line1 to storage, reactivation,

or other treatment, or, if desired, a portion of the used aluminumchloride-containing sludge may be recycled from line 1 through line 8 toline I, already mentioned, through which a mixture of fresh naphtha anda gas containing hydrogen and hydrogen chloride is being conducted todestructive hydrcgenation.

Said gas containing hydrogen and hydrogen chloride separated from thedestructive hydrogenation products may be directed from separation zone6 through line 9 in which it may be commingled with fresh hydrogenchlorideadmitted from an outside source through line l0 and thenceintroduced to line I, already mentioned, through which naphthav ischarged to de-4 spectively, as hereinafter setforth.

'Unconvertedlfnaphtha .and products boiling higher than hexanes whichmay be referred to. as Cv and higher hydrocarbons may a be conducted-from separation zone 6 through line I5,

Vtherein commingled by way of line 2| with hydrogen and light gasesformed in the process as hereinafter set forth, and thence admitted todehydrogenation zone 'I6 Whichmay comprise a reactor. or group ofreactors containing a suitable dehydrogenating catalyst asaforementioned and maintained at a temperature betweenvabout 800 andabout 1200 F. under a pressure of from substantially atmospheric toapproximately 150 pounds perfsquare-inch. Under these conditionsnormally liquid parailinic hydrocarbons present may be dehydrogenated tothe corresponding normally liquid volei'lns while naphthenic hydrocar-.bons may fundergo conversion to aromatic hydrocarbons.

If desired, propane being discharged through line I3 may be directedthrough alternative line II to corn-mingle with the mixture beingsubjected `to dehydrogenation in zone I6. The total product may bedischarged from dehydrogenation zone I6 through line I8 to separationzone I9 which may comprise absorbing and stripping equipment of'adequatedesign for separating a mixture of hydrogen and light gases, such asmethane,ethane, etc., from higher boiling and generally normally liquidhydrocarbons contain-l ing olenns formed by dehydrogenation in zone I6.as hereinabove set forth. Said mixture of hydrogen and light gases maybe directed from separation zone I9l through line 20,to line 9, alreadymentioned, through which hydrogen, hydrogenchloride, and light gases arebeing recycled to further use in destructive hydrogenation zone 2. Aportion of said mixture of hydrogen and light gases being directedthrough line 20 may be conducted. therefrom through line 2l to comminglewith said unconverted naphtha and products boiling higher than hexanesbeing conducted to dehydrogenation zone I6.

` Said hydrocarbons containing olens separated in separation zone I9from a mixture of hydrogen and light gases may be directed through line22 and therein commingled with isobutane,

or another isoparailin, being conducted from separation zone 6 throughline I4, already mentioned. The resulting commingled mixture maybedirected from line 22 to alkylation zone 23 which may comprise asuitable reactor provided with adequate agitating, cooling, and/orheating `devices for maintaining the uniform temperature preferable foralkylation in the presence of a catalyst I and 210 F. Means not shownmay be provided for adding fresh catalyst and for removing used catalystduring the-course o f the aforementioned alkylation reactions, Alsoalkylation of isobutane by normally liquid olefins may be effected inthe presence of a prealcinedv composite of an acid of` phosphorus and agenerally siliceous adsorbent in a reactor or plurality of reactorscontaining the granular catalytic material and operated at 'atemperature between about 600 and 900 F. under a pressure within theapproximate limits of 1000 and 3000 pounds per square inch.

Normally liquid products formed by such a1- kylation and admixed withunconverted isobutane and with normally liquid hydrocarbons boilingabove hexane which were not dehydrogenated in zone I 6 may be dischargedfrom ,alkylation zone 23 through line 24 to separation zone 25 whichmayA comprise fractional distilling equipment of adequate design forseparating a substantially saturated and alkylate-containing motor fuelfrom unconvertedisobutane and lighter gasessuch as propane which may bepresent when this gaseous hydrocarbon is admixed with the liquidhydrocarbons being subjectedto dehydrogenation as hereinabove set forth.Said unconverted isobutane may be recycled from separation zone 25through lines 26V and 22 to further alkylating treatment. 'Ilhe motorfuel fraction containing of the invention:

urated hydrocarbons not dehydrogenated in zone I6 and presentin saidmotor fuel may be separated from thealk'ylation product in separatingvzone'25 and thence yrecycled by means notv shown to furtherdehydrogenation treatment in Zone i6 in' order to provide sucientnormally liquid olefor alkylating substantially al1 offthe iso-v butanederivedfrom the 'primary destructivel hydrogenati'on step of theprocess. f y' Y The following specific example is presented. as

illustrative off the process as it maybe conclueted, using ai processiloW'as hereinabove described, al-

though this 'illustrative material should. not`V be miscoristr'ued tolimit the'y generally broad scope A substantially normal 'paraffinhydrocarbon vention and particularly its commercial value are evidentfrom the preceding specification `and limited numerical materialpresented although I claim as my invention:

. 1. A process for converting asubstaritiall'y7 satrated hydrocarbonfraction of motorfuel boiling range and relatively low antiknock valueinto a .substantially 'saturated motor fuel of improved antiknock value[which comprises treating said hydrocarbon fraction, with aluminumchloride, hydrogen, andhydrogen chloride to produce sub-- stantialyields'offisobutana a fraction containing .branchedilchainh.pentanes andhexanes.. and `a higher boilinghydrocarbon fraction; catalyticallydehydrogenating',saidlhigher boiling hydrocarbon fraction ".toform adehydrogenation product containing a substantial. proportion ofnormally` liquid. olefins; andsubjecting said isobutane and "saiddehydrogenationproduct to catalytic alkylafraction containing 2% byvolume of hexane, 10%

'.heptane, 13`% octa`ne', 25%nonane,` 20% decane, undecane, and 10% byvolume of. higher boilinghydrocarbons may be heatedat 165" F. in

the presence of hydrogen undera pressure of l 1600 pounds per squareinch'iand in the presence of 10% by weight of aluminum chloride and 1.2%by Weight of hydrogen chloride, The products of this treatment mayconsist of 25.8%by weight of isobutane; 24.5% of a pentane fractionywith 85.5 octane number and approximately 90% isopentane'content; 9.7%of a hexane fraction with 80 octane number; 27.2% of a fraction with 5.5octane number comprising essentially heptanes and higher boilingproducts; 4.2% of non-condensible gases; 4.9% of hydrocarbonaceousresidue; and 3.3% loss.

The fraction comprising essentiallyheptanes and higher-boilinghydrocarbons may-be vaporized and commingled with 'approximately 4 moleper cent of water vapor and the commingled mixture then subjected at1020 F. under substantially atmospheric pressure to Contact with acomposite comprising essentially 8% by weight vof chromium sesquioxideand 92% by Weight of activated alumina to form a product containingsubstantial proportions of normally liquid olens.

Isobutane derived from destructive hydrogenaltion of the parafnicfraction charged may be'alkylated by said normally liquid olefins in thepresence of sulfuric acid of 95% concentration at 45 F. under a pressureof200 poundsl per s quare inchl to form a substantially saturatedalkylate admixedwithheptane and higher boilinghydrocarbonsremaining-unconverted after the original treatmentV with thechromium sesquioxide-alumina catalyst. Av sufiicient proportion*v ofvsaid heptane -and higher boiling hydrocarbons maybe separated from saidmotor fuel by 'fractional distillation and thenA recycledtofurtherrdehydrotionftoform a' substantially saturated alkylatecomprising essentially hydrocarbons of motor fuel boiling range and highantiknock value.

2. A process for convertinga substantially sat- *urated hydrocarbonfraction of motor fuel boiling range and relatively low antiknock valueinto a substantially saturated motor fuel of improved antiknock valuewhich comprises treating said hydrocarbon fraction with aluminumchloride, hydrogen, and hydrogen chloride at a temperature between about100 and about 500 F. under a pressure within the approximate limits of300 and`2500 pounds per square inch to produce substantial yields ofisobutane, a fraction containing branched chain pentanes and hexanes,and a higher bolling hydrocarbon fraction; catalytically dehydrogenatingsaid Vhigher boiling hydrocarbon fraction to form a dehydrogenationproduct containing a substantial proportion of normally liquid olens;and subjecting said isobutane and said dehydrogenation product tocatalytic alkylation to form a substantially saturated alkylatecomprising ,essentially hydrocarbons of motor fuel boiling range andhigh antiknock value.

3. A process for converting a substantially sat'- urated hydrocarbonfraction of motor fuel boiling range and relatively low antiknock valueinto a substantially saturated motor fuel of improved antiknock valuewhich comprises `treating said hydrocarbon fraction with aluminumchloride, hydrogen, and hydrogen chloride to produce substantial yieldsof isobutane, a fraction 'containing branched chain pentanes andhexanes, and a higher boiling hydrocarbon fraction; subwith adehydrogenating catalyst at a temperature between about 800 and aboutl200 F; under genation to produce oleiins necessary for alkylatingsubstantiallyall of the isobutane produced in theprimary destructivehydrogenation step.

Thus by combining destructive hydrogenation, t dehydrogenation, andalkylation it is possible to obtain approximately 34% by weight of japentane-hexanefraction of approximately 84 octane number, 45 `by weightof a substantially saturated alkylate of gasoline boiling range and 90octane'numloer,y and 10% by Weight of a higher boiling residue fromanaphtha fraction of relatively low antiknock value.

The character of the process of the present ina pressure offromsubstantially atmospheric to approximately 1 50 pounds per square inchto form a; dehydrogenation product containing a substantial proportionof normally liquid olefns;

and subjecting said isobutane and said dehydrogenation product to`catalytic alkylation to form a substantially saturated alkylatecomprising essentially hydrocarbons of motor fuel boiling range and highantiknock value..

4. Aypioces's for converting a substantially saturated hydrocarbonfraction of motor fuel boiling range and relatively low antiknook valueinto a substantially saturated motor fuel of improved antiknock valuewhich comprises treating said hydrocarbon fraction with aluminumchloride,

hydrogen, `and hydrogen chloride at a temperature between about andabout 500 F. un-

`der a pressure within the approximatev limits of 300 and 2500 poundsper square inch to produce substantial yields of isobutane, a fractioncontaining branched chain pentanes and hexanes, and a higher boilinghydrocarbon fraction;

vsubjecting said higher boiling fraction-,in the presence of from about0.1 to about mole per cent of water vapor to contact with adehydrogenating catalyst comprising essentially a major proportion of asubstantially inert carrier and a relatively smaller proportion of anoxide of an element selected from the members of the left-hand column ofgroup V of the periodic table consisting of'vanadium, columbium, andtantalum to form a dehydrogenation product containing a substantialproportion of normally liquid olens; and subjecting said isobutane andsaid dehydrogenation product to catalytic alkylation to form asubstantially saturated alkylate comprising essentially hydrocarbons o1'motor fuel boiling range and highantiknock value.

5. A process for converting a substantially saturated hydrocarbonfraction of lmotor fuel boiling range and relatively low antiknockvalueinto a substantially saturated motor fuel of improved antiknockvalue which .comprises treating said hydrocarbon fraction with aluminumchloride, hydrogen, and hydrogen ychloride at a temperature betweenabout 100 and about 5009 F. under a pressure within the approximatelimits of 300 and 2500 pounds per square inch to pro- -duce substantialyields of isobutane, a fraction containing branched chain pentanes andhexanes, and a higher boiling hydrocarbon fraction; subjecting saidhigher` boiling fraction in y the presence of from about 0.1 to about 10moleI percent of water vapor to contact with a dehydrogenating catalystcomprising essentially a major proportion of a substantially inertcarrier and a. relatively smaller proportion-of an oxide of an elementselected from thev members of the left-hand column of group VI of theperiodic table consisting of chromium, molybdenum, tungsten, and uraniumto form a dehy-l drogenaton product containing a substantial proportionof normally liquid olens; and subjecting said isobutane and saiddehydrogenation product to catalytic alkylation to form a substantiallysaturated alkylate comprising essentially hydrocarbons of motor fuelboiling range and high antiknock value.

6. A process for converting a substantially saturated hydrocarbonfraction of motor fuel boiling range and relatively low antiknock valueinto a substantially saturated motor fuel of improved antiknock valuewhich comprises treating said hydrocarbon fraction with aluminumchloride, hydrogen, and hydrogen chloride at a tem- Derature betweenabout and about 500 F. under a pressure within the approximate limits of300 and 2500 poundsper square inch to produce substantial yields ofisobutane, a fraction containing branched chain pentanes and hexanes,and a higher boiling hydrocarbon fraction; subjecting 4said higherboiling fraction in the presence of between about 0.1 and 10 mole percent of water vapor and a hydrogen-containing gas derived from theprocess to contact with a dehydrogenating catalyst comprisingessentially a major proportion of a substantially inert carrier and arelatively smaller proportion of an oxide of an element selected fromthe members of the left-hand column of group VI of the periodic tableconsisting of chromium, molybdenum, tungsten, and uranium to form adehydrogenation product containing a substantial1 proportion of normallyliquid olens; and subjecting said isobutane and saiddehydrogenationproduct to catalytic alkylation to form a substantially saturatedalkylate comprising essentially hydrocarbons of motor fuel boiling rangeproved antiknock value which comprises contin.

uously treating said hydrocarbon fraction with aluminum chloride,hydrogen, and hydrogen chloride to produce substantial yields ofisobutane, a fraction containing branched chain pentanes and hexanes,and a higher boiling hydrocarbon fraction; simultaneously catalyticallydehydrogenating saidv higher boiling hydrocarbon fraction to form adehydrogenation product containing a substantial proportion of normallyliquid olens; and continuously subjecting said isobutane and saiddehydrogenation product to catalytic alkylation to-form a substantiallysatu rated alkylate comprising essentially hydrocarbons of motor fuelboiling range and high antiknock value. f

8. A process for producing anti-knock motor fuel from substantiallysaturated hydrocarbon oil, which comprises subjecting the oil tocatalytic destructive hydrogenation such as to produce a substantialquantity of isobutane, separating from the resultant products anisobutane fraction and a fraction higher boiling than hexane, subjectingthe last-named fraction'to catalytic dehydrogenation to form normallyliquid olens, commingling the latter with said isobutane fraction,subjectingthe resultant mixture to catalytic alkylation to react olefinswith isobutane and recovering the resultant alkylate.

RAYMOND E. SCHAAD.

